She was the mother of two kings of Portugal (Afonso VI and Peter II) and a queen of England (Catherine of Braganza).

She married a high ranking Portuguese noble, John, 8th Duke of Braganza, in 1633, during the period of the Iberian Union.

[8][9] It is said that being warned of the dangers of becoming queen of a country that was to face Spain's might, she pronounced the famous words:[citation needed] Antes Rainha um dia que Duquesa toda a vida.

When she was made aware of a failed attempt to murder the King in 1641, she is said to have been one of the members of the Corte, which supported the execution of nobles like the Duke of Caminha.

[citation needed] In 1656, she was named Regent of the Kingdom after her husband's death and during the minority of her son Afonso VI.